Avial (Kerala Mixed Vegetable Curry in Coconut-Yoghurt Sauce)

Avial is closely associated with Kerala's Onam sadya, the elaborate vegetarian feast served on banana leaves during the state's harvest festival, though it is also cooked as an everyday dish in Kerala and parts of Tamil Nadu. Legend credits its invention to Bhima of the Mahabharata, who is said to have thrown together whatever vegetables were on hand during his kitchen work in exile — a folk story that captures the dish's essential character as a way of using up a vegetable basket rather than following a fixed shopping list.

NNWA includes avial in its plant-based nutrition material because it demonstrates, in a single traditional dish, how combining several vegetables with a fat source changes nutrient absorption. Vegetables like carrot and pumpkin carry fat-soluble vitamins such as beta-carotene, which are better absorbed when eaten with a source of fat — here, coconut and coconut oil — rather than boiled and served alone. It is a practical, centuries-old example of a principle nutrition students often first encounter in a textbook.

The most common technique error is overcooking the vegetables into a mush or boiling the dish after the yoghurt is added, which causes the yoghurt to split and turns the texture grainy rather than creamy. Vegetables should be cut into similarly sized batons so they cook evenly, and the yoghurt and raw coconut oil should always be folded in off the heat, right at the end.

The exact vegetable mix varies by household and season — ash gourd, snake gourd and colocasia are all traditional additions or substitutes — which makes avial forgiving and adaptable to whatever is fresh. For a fully plant-based version, the yoghurt can be replaced with a little thick coconut milk, though this changes the dish from its classic vegetarian form into a coconut-only variant.